621 YC Engineering, Product and Design Startups (B2B)

621 YC companies fall under Engineering, Product and Design, YC's B2B subcategory, across every batch since 2005. Each row shows the one-liner, batch, HQ and status, and links to a reconstruction of the company's YC application in the real form.

Companies
621
Top locations
San Francisco, New York and New York City
YC top companies
9
621 reconstructed applications

Read the YC application of all 621 companies

  • Every company's YC application, reconstructed in the real form
  • Filter every batch by industry, country and team size
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The first 100 companies, top companies first

1
Algolia
AlgoliaTopA developer-friendly and enterprise-grade search API.
Winter 2014San Francisco, CAActive
2
Bird
BirdTopThe world’s largest omnichannel communications platform
Summer 2016Amsterdam, NH, NetherlandsActive
7
Optimizely
OptimizelyTopThe first all-in-one operating system for marketing
Winter 2010San Francisco, CAAcquired
10
21st
21stInfrastructure and UI building blocks for the agentic internet
Winter 2026San Francisco, CAActive

That is 10 of 621.

Every company below has its YC application reconstructed in YC Insights. Create a free account to read them all.

Read all 621 applications
11
280 North
280 North
Winter 2008San Francisco, CAAcquired
12
a0.dev
a0.devWe make mobile apps using AI.
Winter 2025San Francisco, CAActive
13
A1Zap by A1Base
A1Zap by A1BaseThe social network layer for AI apps
Winter 2025San Francisco, CAActive
14
Abstra
AbstraAutomate finance operations with Python and AI
Summer 2021Rio de Janeiro, RJ, BrazilActive
15
Actiondesk
ActiondeskAccess all your live data in one place
Summer 2019New York City, NYAcquired
16
Activepieces
ActivepiecesOpen-source, AI-first and no-code business automation tool
Summer 2022San Francisco, CAActive
17
Adam
AdamAI Powered CAD
Winter 2025San Francisco, CAActive
18
Aesthetic
AestheticYour AI-powered creative apprentice 🪄
Summer 2018New York, NYActive
19
Aether
AetherAI sales platform for home services
Winter 2024San Francisco, CAActive
21
Agent FM
Agent FMOne group chat to hear and steer your coding agents.
Summer 2026San Francisco, CAActive
22
Agentic Labs
Agentic LabsAI system design tools for dev teams
Winter 2024New York, NYActive
24
Alex
AlexThe Cursor for Xcode
Fall 2024San Francisco, CAActive
25
Alkali
AlkaliThe smarter way to estimate steel.
Spring 2025San Francisco, CAActive
26
Alkera AI
Alkera AIReliable and safe data engineering and data science agents
Summer 2026San Francisco, CAActive
27
Alokai
AlokaiFrontend Platform for eCommerce
Winter 2021Warsaw, Masovian Voivodeship, PolandActive
29
Aluna
AlunaData for biomedical AI
Summer 2024San Francisco, CAActive
30
Amorphic Labs
Amorphic LabsOpenRouter for Agent Tools
Summer 2026San Francisco, CAActive
31
Andon Labs
Andon LabsAutonomous organizations without humans in the loop
Winter 2024San Francisco, CAActive
32
Anima App
Anima AppDesign to Code & On-brand Vibe-coding
Summer 2018New York, NYActive
33
Antigen
AntigenContinuous offensive security for the enterprise.
Fall 2025San Francisco, CAActive
34
Appcubator
AppcubatorThe easiest way to prototype web applications.
Winter 2013Mountain View, CAInactive
35
Appjet
Appjet
Summer 2007San Francisco, CAAcquired
36
Approxima
ApproximaYour software should build itself.
Winter 2026San Francisco, CAActive
38
Archbee
ArchbeeTURN STATIC DOCS INTO INSTANT ANSWERS
Summer 2021Bucharest, Bucharest, RomaniaActive
41
Artifact
ArtifactAn Collaborative, AI-native IDE for Hardware Engineers
Winter 2025New York City, NYActive
42
Ashr
AshrAutomated Multi-Modal Testing for Agents
Winter 2026San Francisco, CAActive
43
Aspect
AspectBuild UI fast.
Summer 2019San Francisco, CAActive
44
Aspect
AspectIntelligent media storage for creative teams.
Fall 2025New York City, NYActive
45
AtlasGrid
AtlasGridAccelerate Product Iteration
Fall 2025San Francisco, CAActive
47
Atrisa (formerly Refortifai)
Atrisa (formerly Refortifai)AI Agents for Analog Circuit Design
Spring 2026San Francisco, CAActive
48
Attune
AttuneFaster builds, zero effort.
Spring 2025San Francisco, CAActive
50
Aurorin CAD
Aurorin CADClaude code for Mechanical Engineers
Winter 2026San Francisco, CAActive
51
Authologic
AuthologicStripe for online identity verification
Winter 2021RemoteActive
52
Authy
AuthyAuthy is a Two-Factor Authentication platform for developers
Winter 2012San Francisco, CAAcquired
53
authzed
authzedCloud Infrastructure for Authorization
Winter 2021New York, NYActive
54
Autosana
AutosanaAI agents for E2E testing across mobile & web
Summer 2025San Francisco, CAActive
55
Avametric
AvametricSimulate clothes on your body.
Winter 2014San Francisco, CAAcquired
56
Aviator
AviatorGoogle-level engineering productivity suite
Summer 2021San Francisco, CAActive
57
Axolo
AxoloImproving Developer Experience with Streamlined Code Reviews
Winter 2021Paris, Île-de-France, FranceActive
58
Axross Pte Ltd
Axross Pte LtdAI-driven HVAC control system for improved energy performance
Winter 2022Singapore, SingaporeActive
59
Baserun
BaserunObservability and evaluation platform for LLM apps.
Summer 2023San Francisco, CAActive
61
Bayes
Bayes
Summer 2019San Francisco, CAAcquired
64
Bilanc
BilancAI-Powered Engineering Productivity
Winter 2024San Francisco, CAActive
65
bitrig
bitrigVibe code, test, and deploy Swift apps. All from your iPhone.
Summer 2025San Francisco, CAActive
66BitSampleWinter 2008Inactive
67
Blink
BlinkBuild fully functional apps with AI.
Winter 2022San Francisco, CAActive
68
Bloom
BloomBuild and share mobile apps in seconds
Spring 2025Active
70
BotCity
BotCityObservability and Governance for AI-Generated Python scripts.
Winter 2022San Francisco, CAActive
72
Boundo
BoundoUsing generative AI to 10x outbound sales, all on autopilot!
Summer 2022San Francisco, CAActive
73
Bracket
BracketTwo-way syncs between business tools and your database
Winter 2022New York, NYAcquired
74
Brainboard
BrainboardVisually design and manage cloud infrastructures.
Winter 2022New York, NYActive
75
Briefer
BrieferThe collaborative data platform.
Summer 2023São Paulo, SP, BrazilInactive
76
Broccoli AI
Broccoli AIAI-native operating system for home service businesses
Winter 2022San Francisco, CAActive
77
Bronco AI
Bronco AIAI for ASIC Design Verification
Summer 2023San Francisco, CAActive
78
Brushes
BrushesiPad drawing software.
Summer 2010Inactive
79
BuildJet
BuildJetHigh-performance computing cloud
Winter 2023Berlin, Berlin, GermanyActive
80
Button Computer
Button ComputerButton is the wearable AI that can talk.
Winter 2026San Francisco, CAActive
83
Cactus
CactusLow-latency AI engine for mobile devices & wearables
Summer 2025San Francisco, CAActive
84
Caddy
CaddyYour partner for everyday work, lives in iMessage
Fall 2025New York City, NYActive
85
camelAI
camelAIAI software engineer that lives on its own computer
Winter 2024San Francisco, CAActive
86
camfer
camferBuilding the world’s first AI mechanical engineer.
Summer 2024San Francisco, CAActive
87
Canary
CanaryThe first AI QA engineer that understands your code
Winter 2026San Francisco, CAActive
88
Capacitive
CapacitiveThe data gateway for agents.
Spring 2025San Francisco, CAActive
89
Capy
CapyThe IDE for the parallel age
Fall 2024San Francisco, CAActive
90
Cardinal
CardinalYour AI product backlog
Winter 2023Austin, TXAcquired
91
Cedar
CedarExecute the best sales playbook in industry
Winter 2025San Francisco, CAActive
92
Cekura
CekuraVoice AI and Chat AI agents: Testing and Observability
Fall 2024San Francisco, CAActive
93
Cerulion
CerulionOpen source operating system for robots
Summer 2024San Francisco, CAActive
95
Chonkie
ChonkieDeep research on autopilot
Spring 2025San Francisco, CAActive
96
Chordio
ChordioClaude Code design workspace built for product teams
Summer 2022Issaquah, WAActive
97
CircuitLab
CircuitLabOnline circuit simulator and electronic schematic editor.
Winter 2013Redwood City, CAActive
98
Clarus
ClarusLP clarity across private markets
Fall 2024New York, NYActive
99
Clay
ClayFigma for 3D design
Winter 2021RemoteInactive
100
Clearline
ClearlineAI operating system for car dealerships to capture missed revenue
Summer 2022Toronto, ON, CanadaActive

The other 521 companies

Every remaining company in this list, A to Z. Each link opens the company's public page.

ClickpassCluesoClutchco.devCO2StatsCoArenaCoastsCodeAnt AICodeballCodeParrot AICodeStoryCodeStreamCoLabComfy DeployCommand AICompyleConductorConfident AIContinueContrastConvoyCorelayerCorsairCosmicCourierCovalCreative MarketCredictiveCrocodocCuacubicCustomilyCUTRCyberdeskd_modelDaggerDalusdari.devDashblockDashdiveDatafruitDatamodeDataNitroDatasaurDataShareDecentroDecipher AIDeepgramDeepnoteDeepSim, Inc.DeepSourceDeferDelineateDepotDesignbaseDev Tools AIDevCycleDevFlightDimeDiode Computers, Inc.Dioxus LabsDisqusDittoDiversionDocketDockupDomu Technology Inc.DopplerDouble - Coding CopilotDoublezeroDraftaidDraftbitDragoneyeDrDroidDream3DDreamforgeDuckieDucklyEaselEchoes HQEivodEllipsisElphEmbedderEmbedlyEmbraceEmerge ToolsEndlaEntanglEnveloopEnvKeyEvo.DoExlaF2FableFastgenFastshotFeaturePeekFederacyFernFigFileforgeFinchFirebenderFloobitsFlootFlowdashFlowiseAIFloydHubFlutterFlutterFlowFont AwesomeFreebuffFreesoloFrigadeGazeHawkGigaGigacatalystGigsGigsterGitStartGlideGlisten AIGlueGodelaGraphify LabsGreat QuestionGreptileHaikuHamming AIhardware intelligenceHaystackHaystackHeliumHelixDBHeraherdrHeroUIHestus, Inc.highlight.iohillclimbhoop.devHopliteHosshotgluehudHuman BehaviorHumanLayerHumanloopHyperbeamHyperDXHypermileHyperProbeHyrexIambiq TechnologiesIcePanelideate.xyzIdlerInariInconvoInfieldInfracostInkeepInsForgeInspectorInstantIntegrated ReasoningInteguruInterfereIntersect LabsIntunedInvariaion designJamsocketJeevy FabricationJet AdminJitterJuziBotKarate LabsKeepKilvinKimono LabsKitemakerKraftfulLabelFlowLamina LabsLaminarLangfuseLariat DataLarkLattedLeapingLemmaLight Table/EveLightlyLightskiLightsprintLightTwistLightwellLingo.devLocusLuciq (formerly Instabug)LumeLuminaiLunaticLynxLyrebirdMacadamiaMach9Magic PatternsMagicBellMagiCodeMagnaPlayMagnitudeMailgunMaitaiMarblismMarftMarkupwandMartiniMassdriverMastraMemoMergentMesmerMetaplaneMeticulousMetoficoMetoroMidrenderMillionMindeeMinroMintlifyMiomiruMistleMobileBoostMobotMomenticMonosiMonteMonterey AIMOVEdotMoving PartsMovingLakeNangoNarrativeNaytevnCompass TechnologiesNewCraftNewslabsNextmvNimbic AINolocoNotifoNoya SoftwareNozomioNudgePadnumericcal, inc.NuMindNyckelOddpoolOkiOmnaraOmnirefOneGraphOneGrepOnePatchOnlookOpenOpenbaseOpenBuilderOpenFoundryOpenlayerOpenPipeOpenProseOpenRelayOpenToolsOpsolutelyOpticORO AIOuterbaseOuterportPagedrawPalisadePanelsPaperspaceParagonParsePartclPathmindPayloadPaziPelmPensilPhotoniumPierrePinnaclePirrosPixelapsePlaymentPlexePloomberPluggyPolishedPolymetPoplarMLPopSQLPovioPreflightPreloopPretzel AIPrismPrizedProliferatePromptlessPropelAuthProtobasePullRequestPyroscopeQuery VaryQuetzalQueueQuilt DataRaindropRainforestRally UXRRandom LabsRavenReactWiseReadMeReal ArtistsRecall.aiRecipeUIReductorefineRefineTrain AIReflectReframeRefreshReJotRelaceReleaseRelvy AIrenderletRepaintReplicasReplitReploRepromptRequestlyRescaleResendREV1RevenueCatRindlerRivetRiveterRoboflowRoostRovrRubber Ducky LabsRunKitRunLocal AIRuntimeRunwayRutterSage AISails Co.Saphira AISBX RoboticsScaphold.ioScoutzieSculptSeamSegments.aiSemioticSendbirdSendoSensorSurfSentrialSerialShadeformShogunshortkitShortLoopSIDSigmanticAISigOptSilimateSilogySimanticSimplexSimulithicSixaSixtySkyhookSmoothSnapMagicSolari AISolidStageSonarlySourcebotSourceDNASourceressSparklesSpecificSpine AISpurSquire.aiStably AIStack AuthStackqStacksyncStackupStagestagewiseStarSlingStatusPageStellon LabsStillwindStitch TechnologiesStoria AIStorylineStructStructured LabsSubtracesudocodeSuperb AIsupercontrastsuperglueSuperlogSupernovaSupersetSuperwallSurgeSweepSweetspotSwiftypeSynthetic SciencesSynthetic SocietyTagsafeTalcTaloflowTempoTerra APITesterArmyTestmunktestRigorThe Context CompanyThe Synthesis CompanyTheneoTheoremTiptapToDesktopToolifyTopologicalTraceRoot.AITrainLoopTremorTriggerTrigger.devTrimTriplitTruffle AITumultTuskUiflowUltralightUnflowUnsloth AIunSurveyUpLabsUpverterURXUser HeroValgoVango AIVapiVariantVellumVendoVeriffVerihubsVersiveVesselVibeVibe KanbanVimmerseVisibl Semiconductorsvly.aiVoiceryVoidVokerVybeWaferWarpBuildWaspWatchsendWeavWeavewebapp.ioWebCakeWebinyWild MooseWildcardWinterWit.aiWithIdaWorkers IOXkitYhatZarazZatannaZelos CloudZenbuZeplinzeroheightZillabyteZumo Labs

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About this list

This list is part of Round Funded, an investor database and outreach platform for founders. It covers 60,000+ active VCs, angels, family offices and accelerators with verified contacts, lets you send pitches from your own Gmail, and includes a free Data Room for your raise.

Frequently Asked Questions

How many Y Combinator companies are in Engineering, Product and Design (B2B)?

This directory lists 621 YC companies in Engineering, Product and Design (B2B), out of 6,207 across every batch since 2005. The count updates when the directory is refreshed, and every one of them is on this page with a link to its public profile.

Are the YC applications on these pages real?

No. YC keeps submitted applications private. Every application linked from this list is a reconstruction: the real YC form questions, answered from the company's public data. The Company section is free on each page; the rest opens in YC Insights.

Which companies on this page are best known?

Algolia, Bird and Cognito lead the table above. YC marks 9 of the 621 companies here as top companies, its own list of the highest-valued and highest-revenue alumni.

How do I use this list when applying to YC?

Pick five companies on this page whose product is closest to yours, read their reconstructed applications side by side in YC Insights, and note how each answers the same question. Then write your own answers to that standard.

Where does this data come from?

From YC's public company directory, refreshed by batch, with each company's status, industry and location as YC reports them. Round Funded adds the reconstructed application and the founder profiles; nothing private is published.

What is Round Funded?

Round Funded is an investor database and outreach platform for startup founders. It lists 60,000+ active investors with verified contacts, filtered to recent investment activity, and lets founders send personalized pitches from their own Gmail, track replies, and share a free Data Room. Round+ starts at $99 per month with a 3-day trial.